In recent years, various technologies have been proposed in data communication fields. For example, Patent Literature 1 below proposes technology related to a Machine-to-Machine (M2M) solution. To be specific, the remote management system written in Patent Literature 1 uses the Internet protocol (IP) multimedia subsystem (IMS) platform (IS), and through disclosure of presence information by a device or instant messaging between a user and a device, an interaction between an authorized user client (UC) and a device client is achieved.
On the other hand, in acoustic technology fields, various types of array speakers that can emit acoustic beams are being developed. For example, Patent Literature 2 below describes array speakers in which a plurality of speakers forming a common wave front are attached to a cabinet and which control amounts of delay and levels of the sounds given out from the respective speakers. Further, Patent Literature 2 below describes that array microphones having the same principle are being developed. The array microphones can voluntarily set the sound acquisition point by adjusting the levels and amounts of delay of output signals of the respective microphones, and thus are capable of acquiring the sound more effectively.